bugfix: type functions need to be mfs

1 files changed, 1 insertions, 1 deletions

diff --git a/neb/std/core.py b/neb/std/core.py
index 15cb257..344ac74 100644
--- a/neb/std/core.py
+++ b/neb/std/core.py
@@ -282,7 +282,7 @@ def interpretType(symbol, args, env, ns):
         raise InterpretPanic(symbol, "parent must be a valid type", parent_type)
 
     func = evaluate(args[2], env, ns)
-    if not isinstance(func, Function):
+    if not isinstance(func, MultiFunction):
         raise InterpretPanic(symbol, "validation must be a :func", func)
 
     new_type = UserType(name, parent_type, func)